/**
  * Copyright 2006 IBM Corporation.
  */
package javax.portlet;

/**
 * The <code>ResourceRequest</code> interface represents the request
 * send to the portlet for rendering resources.
 * 
 * It extends the ClientDataRequest interface and provides resource request
 * information to portlets.
 * <p>
 * The portlet container creates an <CODE>ResourceRequest</CODE> object and
 * passes it as argument to the portlet's <CODE>serveResource</CODE> method.
 * <p>
 * The <code>ResourceRequest</code> is provided with the current portlet mode, window state, 
 * and render parameters that the portlet can access via the 
 * <code>PortletResourceRequest</code> with <code>getPortletMode</code> and, 
 * <code>getWindowState</code>, or one of the <code>getParameter</code> methods.   
 * ResourceURLs cannot change the current portlet mode, window state or 
 * render parameters. Parameters set on a resource URL are not render parameters 
 * but parameters for serving this resource and will last only for only 
 * this the current serveResource request.<br>
 * If a parameter is set that has the same name as a render parameter that this 
 * resource URL contains, the render parameter must be the last entry in the 
 * parameter value array. 
 * 
 * @see ClientDataRequest
 * @see ResourceServingPortlet
 * @since 2.0
 */
public interface ResourceRequest extends ClientDataRequest {

    /**
     * This property is set by the container if the container
     * has a cached response for the given validation tag. The property can be
     * retrieved using the <code>getProperty</code> method. 
     * <P>
     * The value is <code>"portlet.ETag "</code>.
     */
    public static final String ETAG = "portlet.ETag";

    /**
     * Returns the validation tag if the portlet container
     * has a cached response for this validation tag, or
     * <code>null</code> if no cached response exists.
     * <p>
     * This call returns the same value as 
     * <code>ResourceRequest.getProperty(ResourceRequest.ETAG)</code>.
     * 
     * @return  the validation tag if the portlet container
     *          has a cached response for this validation tag, or
     *          <code>null</code> if no cached response exists.
     */
    public String getETag();
    
    /**
     * Returns the resource ID set on the ResourceURL or <code>null</code>
     * if no resource ID was set on the URL.
     * 
     * @return  the resource ID set on the ResourceURL,or <code>null</code>
     *          if no resource ID was set on the URL. 
     */
    public String getResourceID();
 
    /**
     * Returns a <code>Map</code> of the private render parameters of this request.
     * Private parameters are not shared with other portlets or components.  
     * The returned parameters are "x-www-form-urlencoded" decoded.
     * <p>
     * The parameters returned do not include the resource parameters that
     * the portlet may have set on the resource URL triggering this
     * <code>serveResource</code> call.
     * <p>
     * The values in the returned <code>Map</code> are from type
     * String array (<code>String[]</code>).
     * <p>
     * If no private parameters exist this method returns an empty <code>Map</code>.
     *
     * @return     an immutable <code>Map</code> containing private parameter names as 
     *             keys and private parameter values as map values, or an empty <code>Map</code>
     *             if no private parameters exist. The keys in the parameter
     *             map are of type String. The values in the parameter map are of type
     *             String array (<code>String[]</code>).
     */
    public java.util.Map<String, String[]> getPrivateRenderParameterMap();
    
    /**
     * Returns the portal preferred content type for the response.
     * <p>
     * The returned content type should be based on the HTTP Accept header 
     * provided by the client.
     * 
     * @return preferred content type of the response
     */

    public String getResponseContentType();


    /**
     * Gets a list of content types which the portal accepts for the response.
     * This list is ordered with the most preferable types listed first.
     * <p>
     * The returned content types should be based on the HTTP Accept header 
     * provided by the client.
     *
     * @return ordered list of content types for the response
     */

    public java.util.Enumeration<String> getResponseContentTypes();

	/**
	 * Returns the cache level of this resource request.
	 * <p>
	 * Possible return values are: 
	 * <code>ResourceURL.FULL, ResourceURL.PORTLET</code> 
	 * or <code>ResourceURL.PAGE</code>.
	 * 
     * @return  the cache level of this resource request.
     */
	public String getCacheability();

}
